This invention relates generally to a belt abrading device, and more particularly to an exhaust hood for such a device which is mounted for shifting toward and away from the belt under power.
Belt-type abrading machines are known. Such generally include an elongate, endless abrading belt which is trained over a pair of laterally spaced rollers. One of such rollers generally is mounted for shifting toward and away from the other to facilitate replacing the belt, for taking up stretch which occurs in the belt after prolonged usage, and to provide canting of the roller to produce desired tracking of the belt as it is carried over the rollers.
Various styles of exhaust hoods and mountings for exhaust hoods also are known in the prior art. These include hoods as illustrated in U.S. Pat. No. 3,872,627 to Schuster wherein a hood is mounted for swinging about a pivot axis spaced from the roller and may be manually shifted away from the roller. Another swingably mounted hood portion is illustrateed in U.S. Pat. No. 3,889,429 issued to Zuercher.
A hood carried in a preselected position relative to one of the rollers about which an abrading belt is trained is shown in U.S. Pat. No. 760,834 to Yarnell.
Other patents of interest illustrating exhaust hoods are shown in U.S. Pat. Nos. 2,279,782 to Fowler, 3,837,383 to Ko, 1,079,032 to Solem, 2,011,984 to Rosenberger, and 2,120,888 to Eaddy.
None of the above noted prior art devices appear to provide powered means for shifting the hood toward and away from the abrading belt, as may be desirable for shifting the exhaust out of the way quickly should a belt break in the apparatus. Further, none of the others appear to provide means for positively holding the hood under pressure in a preselected position relative to the belt during operation, with the ability if needed to shift the hood under power, quickly away from belt.
A general object of the present invention is to provide the above set out features not found in the prior at noted above.
A more specific object is to provide in belt abrading apparatus novel mounting for an exhaust hood which is operable under power to hold the hood, under usual operating conditions, in a preselected position relative to the belt, and upon initiation of a predetermined occurance, to cause the hood to be moved under power quickly away from the abrading belt.
A further object of the present invention is to provide such a novel device in which means is provided for sensing continuity of the belt, and upon sensing discontinuity of the belt to actuate the system for shifting the hood quickly away from the belt.
Yet another object of the present invention is to provide novel control means operable to produce slow and controlled movement of the hood toward its usual operating position a preselected distance from the belt, but to produce substantially rapid movement of the hood in the opposite direction to shift it out of the way of the belt.
These and other objects and advantages of the present invention will be more fully apparent as the following description is read in conjunction with the drawings.